verb (v)

• destroy property or hinder normal operations(verb.social)

  Synonym:
  counteract, countermine, sabotage, subvert, weaken
  

  source: wordnet30
• hollow out as if making a cave or opening(verb.contact)

  Synonym:
  cave
  

  source: wordnet30
• To excavate the earth beneath, or the part of, especially for the purpose of causing to fall or be overthrown; to form a mine under; to sap; as, to undermine a wall.(verb)

  source: webster1913